1. Field of the Invention
The present invention generally relates to a projection system, an image forming apparatus, and a correction method, a system, and a recording medium (program). More specifically, the present invention relates to a projection system for projecting an image on a projection body by a plurality of projectors, an image processing apparatus included in the projection system, a correction method performed by a computer, a system including a program for realizing the image processing apparatus and a projection apparatus, and a recording medium storing a program for realizing the image processing apparatus.
2. Description of the Related Art
Recently, more and more attention has been paid to a multiple projection technique in which a plurality of projectors are arranged in a manner so that the projection images from the projectors are overlapped with each other in overlapped areas, so that a single and high-resolution image can be projected on a screen.
It is known that such a multiple projection technique is disclosed in Japanese Patent No. 3908255 (“Patent Document 1”). In the image projection system in Patent Document 1, in the correction, a reference image having four or more characteristic points whose coordinate positions are already known is projected on a screen from each of projectors. Here, the reference image refers to a known image in which, for example, bright spots or crosses are arranged at a constant interval.
Then, the positions of the characteristic points on the reference image captured (imaged) by a digital camera are detected. Further, based on the detected positions of the four or more characteristic points of the projectors, the projection images of the projectors are transformed and the overlapped area is detected and a blending process is performed. By projecting the transformed and the blending-processed images on the screen by the projectors in a manner such that the images are arranged so as to have the overlapped area with each other, a single and high-resolution image can be projected.
In addition, there is a known technique about a correction method in the multiple projection or a stack production (see, for example, Japanese Patent Laid-open Publication No. 2013-074475 (“Patent Document 2”)).
In the related art projection system described above, a status is assumed in which a projection can be made without especially taking care of a position of a projection image in a wide screen like a wall. However, there may be a case in which a projection image is desired to be imaged to fit within a plane screen which is separated from a wall like a white board with legs for an exhibition event, advertisement, etc., or a projection image is desired to be imaged to fit within a projection area of a dedicated screen which is attached to a wall (without being separated from the wall) having patterns such as marble stone.